


Detective Stiles Stilinski and the Case of Derek Hale’s Mysterious Mate

by dearericbittle (dutchmoxie)



Category: Teen Wolf (TV)
Genre: Banter, Clueless Stiles Stilinski, Denial of Feelings, Erica Reyes & Stiles Stilinski Friendship, Future Fic, M/M, Mates Derek Hale/Stiles Stilinski, Post-Season/Series 02 AU, Sterek Week 2019, Werewolf Mates, sterekmystery
Language: English
Status: Completed
Published: 2019-10-25
Updated: 2019-10-25
Packaged: 2021-01-03 06:21:30
Rating: Teen And Up Audiences
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 5,553
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/21174845
Author URL: https://archiveofourown.org/users/dutchmoxie/pseuds/dearericbittle
Summary: Mates are a thing. A werewolf thing. Which is fine and shit, but finding out that Derek fucking Hale has a mate? That gets to him. And seeing as Derek won’t tell him who it is, well… Guess that means this is a job for Detective Stiles Stilinski - if he’s not too distracted by his traditional banter with Derek.





	Detective Stiles Stilinski and the Case of Derek Hale’s Mysterious Mate

**Author's Note:**

  * For [christinesficrecs](https://archiveofourown.org/users/christinesficrecs/gifts).

So apparently werewolves have mates. Like, soulmates. Like, bonded for the rest of their life, living happily ever after, other half, two sides of the same coin, actual fucking soul mates. Stiles really doesn’t know how the discussion somehow got from the terrible werewolf knotting porn Erica was making fun of to a discussion of how mating is basically marriage plus. No divorce allowed - or even possible. 

That and how the sex is so much better when you’re mated. Which is a thing he doesn’t think he’ll ever need to know (why would he?) - but it is also completely unsurprising that Erica still feels the need to share that information. There is a lot that can be said about his Catwoman, but her not being proud of the awesome partner she snared for herself is not one of them. 

Erica and Boyd came back changed from their Alpha Pack kidnapping, having been forced to rely only on each other. They’d built a relationship in their months apart from the pack, and were now suddenly able to communicate without using actual words. They’d worked through their traumas side by side afterwards, with the support of their pack - Derek’s pack. It’s sort of Stiles’ pack too, though, by now. 

He says sort of because well, he’s not in Beacon Hills that much anymore and his involvement in supernatural shenanigans has devolved into the occasional bit of tricky research using his dorm room’s annoyingly crappy WiFi. 

Stiles Stilinski is almost normal now. And it’s so fucking boring, but no matter how much he pushes, Derek seems determined to keep him out of pack business. Because apparently school matters now, and there’s others who can pick up the slack. 

Which, rude. He thought Derek and him had something special. 

No, not like that. As if. He means an ally/frenemy type deal where they trust each other with their lives and know way too much about each other’s dark and dirty secrets, but they have no idea how to communicate without a supernatural crisis motivating them. 

At least Derek’s a better Alpha these days. It only took him forever, but he’s managing. Stiles is close to graduating from college - that’s how long it’s taken him. 

Okay, so maybe Stiles is a little impressed. A little. 

“Batman,” Erica drags him from his thought spiral with a tickle with her claws. 

Motherfucker, she knows how ticklish he is and she totally does it on purpose. He never should have let her force herself into the Stiles’ BFF position after Scott… followed Allison to France after high school and just… didn’t come back, hoping that Europe wouldn’t have this much supernatural bullshit to deal with. 

Maybe that happened because they’re mates. Like, Scott just can’t not be where Allison is at all times. It isn’t stalking, it’s mating. 

“Catwoman,” he almost shrieks - manfully. “Erica, can you not?”

His voice cracks like he’s still a prepubescent boy, but he can ignore that when it makes Erica smile at him so fondly. Sometimes he forgets that he spent a significant amount of his life not knowing that she even existed - 

“How else am I supposed to get your attention?” Erica pouts. “I’m not supposed to hit you with car parts anymore.” 

Ah, the good old days in which no one got along and there was much… senseless violence. He is so glad they’ve moved on from that. Even at a bit of a distance, they still feel like an actual pack now. Like a family, almost. Erica’s basically his sister from another mister at this point, making Boyd his brother in law. Isaac is the douche-y little brother, probably. 

And Derek? 

“Derek’s orders?” Stiles teases. 

“Yep,” Erica grins. “If he’s not supposed to slam you into walls anymore, we can’t push you around either. He didn’t even leave room for a sex exception. A sexception, if you will.” 

His best friend is legitimately the worst, especially because he’d once drunkenly confessed to her that while he didn’t approve of the violence at all, his bisexual awakening had involved a lot of jerking off to Derek pushing him against a wall and just… going for it. His teenage libido was… very active, and Derek starred in a lot of dirty fantasies around Stiles’ sixteenth birthday. 

He’s gotten over that - had long ago. It was just a kink Derek allowed him to explore, somehow. It didn’t have anything to do with Derek himself - because Derek is actually… not his type. 

“The worst,” Stiles complains to Erica. “After this and your sex with Boyd related drooling earlier, you definitely owe me baked goods. A lot of them.” 

Erica doesn’t bake. She doesn’t burn water either, but she’s definitely not the chef in the family - that is all Boyd. Everything he makes is simply to die for, and Stiles takes shameless advantage of Erica’s embarrassing behavior (or the many, many moments in which she provides way too much information) to get more of the good stuff. 

“At least we’re not going to be the only mated couple forever,” Erica rolls her eyes at him, but at least she’s no longer messing with him. 

Or is she? Because this just sounds like the set-up to a joke - probably at Isaac’s expense, because Erica does so enjoy teasing him. 

“Isaac finally making it official and marrying his own reflection?” Stiles is only half listening as he digs through the fridge. 

Yeah, Stiles and Isaac have never gotten passed the bitchiness, though they’d put their lives on the line for each other in a heartbeat. And have, in the past. Still, it’s much more fun to tease than to be sincere. Being known is fucking mortifying. 

Also, it seems that once again there are empty containers in the fridge. No juice for Stiles. He pours himself a glass of water instead, and declines to offer anything to Erica. 

“Derek’s finally found his mate.” 

Erica says it just when Stiles has taken a gulp of water, leaving him to do a rather awesome spit-take before he completely chokes on thin air. 

Because what the actual fuck? 

* * *

Derek Hale has a mate. Derek met someone and his inner wolf (shut up EL James, this one is totally fucking valid) stood up and took notice. Instead of the usual, where people take notice of Derek right away and Derek just shoves his hands in the pockets of that damn leather jacket that just always seems to survive any potential apocalypse. And he just… doesn’t notice anyone. Not people outside of the pack, not really. 

Stiles is reasonably sure Derek has had sex over the past few years - Erica has complained about the sex smells at the new Hale House occasionally in their weekly phone calls - but there hasn’t been a regular boy- or girlfriend. Not after Jennifer/Julia/YoSaffBridge. 

Because boy, that was not fun for anyone, least of all Derek. 

This will be, though. This being Derek finding a mate, a soulmate, an actual partner. Someone who is perfect for him, someone who will know how to get through to him and help him run the pack he’d actually managed to establish over the course of the last five years. 

Someone who treats Derek like he deserves to be treated - with a solid sense of humor to go up against the brows of sass, a decent amount of knowledge about wolfy habits, and patience and softness as well as enough sharp edges to keep the balance. 

Clearly this person exists, maybe even in Beacon Hills. He’ll meet them soon, he just knows it - Derek can’t stay private about this forever. Can he?

He’s mere days away from his graduation, and he knows that the pack - or at least a decent part of the pack - is going to come out for the ceremony, completely ignoring any rules about the amount of tickets that Stiles is allowed to purchase. Because they’re family, Erica pointedly told him, and family shows up for each other, if at all possible. 

Will Derek show up? Will he bring his mate? 

Stiles has not been subtle about interrogating Erica - and for once she has been surprisingly reticent to reveal anything. Which is just suspicious, really, but maybe Derek has asked her for some privacy while he gets to know his mate a little better. Throwing the entire pack at them immediately would probably lead to anything but a happy ending for the soulmates. 

The pack probably doesn’t want to scare them off, if that’s even possible with mates. Stiles knows very little about werewolf mates, and the internet is just a treasure trove of wrong information (and porn, mostly porn). So detective Stilinski is on the case, and he’ll be finding out all the ins and outs of mating. 

And he’s damn well going to find out who Derek’s mate is. He has to know his other pack parent, after all. Ew, no, not like Derek is like a dad to anyone in the pack. No, they’re all adults, he’s just the older brother who’s been around the block a couple times, maybe? Not to Stiles, but to Isaac, and Boyd, and Erica, and even Jordan and Lydia, and Kira and Malia. Jackson might be in denial still, but at least Danny knows better. 

(The pack is no longer mostly comprised of wolves. It makes them better. More balanced. And Stiles doesn’t want anyone to come in and upset that balance.)

“Hey Der-Bear,” he finally gives in and just calls Derek. 

He’s an asshole about it, of course, because Derek can’t actually know that Stiles cares about him and… wants him to be happy. Ugh. The worst. 

“Mieczyslaw,” Derek returns. 

“You’re the worst,” Stiles is rolling his eyes, and he knows that Derek knows that. “Seriously, here I am calling you on the eve of my graduation, out of the goodness of my heart…” 

Derek snorts ungracefully at that, which, fuck him. He’s such an asshole, because he’s just always calling Stiles out on his shit and being obnoxious about how well he knows Stiles now and it’s… Mortifying, this whole being known ordeal. Especially coming from Derek, the guy he tried to have arrested several times, the guy who tried to make Stiles saw off his fucking arm when they barely even knew each other. 

And it’s just… He can’t be friends with that guy. Frenemies, packmates, allies… Sure, he can do that. 

“You’re such a dick,” Stiles points it out yet again. 

“The biggest,” Derek is bringing out the exact kind of sass that makes Stiles choke on thin air. 

Because fuck Derek for making Stiles think of his dick for no apparent reason. Stiles doesn’t want to be thinking of this, no sir. That’s just… That would be wrong. 

Derek interrupts his sputtering. “You’d better not be calling to ask me to fact check the porn you’re watching. Not again. Just ask Erica. I’m sure she’s happy to do a tell all.” 

Oh right, that is totally a thing he’s done to Derek. He was drunk and horny - yes, he knows that is a terrible excuse, but it also has the advantage of being completely true. His twenty-first birthday party was… stupidly lonely, because of course there was a Pack emergency that prevented his friends from coming out for it. So he got white boy wasted and watched too much werewolf porn, because… Well, that’s just his brain for ya. 

And then he called Derek, like an asshole, mad at him for having totally valid reasons for not visiting Stiles on his birthday. And really, why did it matter that  _ Derek _ hadn’t shown? It shouldn’t have, but Stiles was ready to be an asshole anyway. 

“Erica is too happy telling me way too many things,” Stiles groans dramatically. “Did you know that mated sex is so much better than regular sex? Because I do now. Not from experience, of course, because the entire world would know if that happened, but just from your beta’s big mouth. Boyd is a lucky man, he really is, and I love her to death, but sometimes I want to ask her to not. N-O-T. No K in there. That’s just mated people sex, I’m sure.” 

Hah, like boring old people sex - and that is not something he wants to think about, especially since Melissa and his Dad are coming up on their first anniversary (which, finally). Who knew getting kidnapped by a crazy Darach would succeed where all of Stiles’ crazy plans had failed? 

Not the point, though. The point is grilling Derek and finding out everything about werewolf mating, and Derek’s mate in particular. 

Curiosity may have killed the cat, but satisfaction brings it back. 

“Werewolves do not have knots, Stiles,” Derek is exasperated, because Stiles wants him to be. 

If Derek is frustrated, he is more likely to reveal information that he doesn’t intend to reveal. It is a trick Stiles has developed after many a fruitless prying session on the phone with Derek. He doesn’t get to do this in real life nearly enough these days. 

“I know, Dorkwolf,” Stiles just really enjoys messing with Derek. “But I didn’t think mating was real either, until Erica told me. You have to keep me updated on wolf stuff, dude. You’re the Alpha, and the harmless human needs to know these things. All of the things, Derek. All of them. Lives could depend on it.” 

Okay, so maybe he is missing out on a promising career in the Theatre. Or just a soap opera, but still. It is much easier to start with the dramatics when he’s on the phone with Derek - anything that’s less than truthful will be called out in a heartbeat if they’re ever face to face again - and it’s been a while since that happened last. 

Who’s been avoiding who, he wonders. 

“You’re full of shit, Stiles,” Derek isn’t letting him have this one. “Harmless my ass.” 

And what an ass. 

Not the point, not the point. 

“Aw, thanks, honey-wolf,” Stiles is just piling on the jokes. “I’m reminding you of this when you’re trying to keep me from fighting the bad guys.” 

Which is bound to happen again at some point. Just because Stiles has a little bit of magic now (thanks Deaton for being supremely unhelpful about the Spark thing, even now), doesn’t mean that Derek sees him as anything other but that annoying, frail human kid he met in the woods that day. And fuck him for that too. 

“Manipulative little shit,” Derek mutters, knowing Stiles can hear him. 

Because Derek is an asshole, just like Stiles is, and Derek’s poor mate is going to have to deal with that for the rest of their life. Which… Stiles hopes they’re enough of a badass to handle that. They probably are, because isn’t that what the concept of mates is all about? 

Stiles does not let go. “Are you sad because you’re not getting mated people sex, Der?”

He meant to turn that pet name into a stupid nickname, but he fails. His voice just… stops at Der somehow, and it doesn’t let him walk it back. 

So he waits for Derek to make fun of him some more. That’s what they do after all. 

“I wish you weren’t coming back,” Derek is rolling his eyes, Stiles is sure of it. 

“Liar,” he hums happily, because Derek misses his awesomeness, he really does. “Just a few days more and you won’t be able to get rid of me again.” 

He cannot wait to be back in Beacon Hills for good, to be with his family again. His Dad is pack too, of course - he’s more involved than Stiles is these days. Not for long though, not when he’s coming back, and coming back soon. 

“However will I cope?” Derek groans. 

Oh, Derek is happy Stiles is coming back. That’s nice. 

When he hangs up on Derek thirty-five minutes later, he realizes he’s totally forgotten to ask more questions about the whole mates deal. 

Well, he’ll have all the time in the world when he’s back in Beacon Hills for good. 

* * *

It is wonderful to be back in his hometown, no matter all the sly looks from the people who still think he’s the same immature teenager he was before he graduated fucking cum laude from a prestigious university. He is glad to be back nonetheless. 

Mostly because it sucks being alone - his college friends are just… people he knows because they shared classes. He hasn’t walked through the fire with them like he has with the pack, and the few friends he’d made never quite understood his connection to the people back home. They joked about Erica being his secret girlfriend so often that Stiles had given up on correcting them midway through sophomore year. It didn’t matter. They didn’t matter. 

But now he’s surrounded by the people who do matter again. 

“Did you actually get lankier since my last visit?” Erica continues to tease him, because that’s just the kind of person she is. “Do they not feed you there? Stiles, I’m extremely concerned about you. Derek! Have you seen Stiles?” 

Of course Derek is there, and of course he goes along with Erica’s bullshit, just so they can embarrass him a bit more. That has to be why Derek looks him up and down closely, those stupid kaleidoscope eyes focused on nothing but Stiles, and it has to be why Erica is actually fucking giggling at him. Or at Derek - he hopes it’s at Derek. 

“I hardly even recognized him,” Derek deadpans, and Stiles is ready for murder. 

“Aw, did you miss me, Der-Bear?” Stiles chooses to merely annoy Derek instead of all out murdering him. “You could have visited - maybe then you would actually recognize me.” 

He’s not bitter, not at all. The Alpha has to take care of the town, after all. He can’t just take off to visit his… pack member? Not like most of the betas have, over the course of the last five years - and even the Sheriff has visited at least once a year. Of course Stiles has been back to Beacon Hills several times, but he hasn’t exactly been able to find time in Derek’s stupidly busy schedule to actually hang out with him.

Does he want to do that? 

“Sounds like  _ you _ missed  _ me _ ,” Derek points out, like a dick. 

“You two are fucking ridiculous,” Erica throws herself down on the biggest and most comfortable couch. “Are you going to do this forever?” 

Wait, so Erica doesn’t think this banter is fun anymore? She’s always encouraged him to tease Derek, claiming that the Alpha needed someone who wasn’t going to fall in line. Stiles still firmly believes that Derek still needs someone to be an asshole to him from time to time, and since no one else has stepped up to the plate… It has to be Stiles. It’s their thing, now. Getting up in each other’s faces - literally this time, as they stand close and just rip into each other. 

“Maybe,” Stiles drags out the word teasingly. “But maybe Derek is going to be too busy having all that mated wolf sex you can’t stop talking about.” 

Subtle he is not, but if he actually wants to get somewhere with this damn mystery, he’s going to have to skip the baby steps and head straight for his target. Wait, is Derek the target or is that the mystery mate? Either way, the metaphor still stands. 

“Damn it, Erica,” Derek growls, and Stiles pretends the vibration doesn’t get to him. 

He hasn’t felt it up close for ages now - he just has to get used to it again. And he will, until Derek stops rising to the occasion because he’s too busy with his mate. So maybe Stiles should get his kicks while he still can. Yeah, that sounds like a solid plan. 

“I’m just happy for you, Derek,” Erica tries her most innocent look. 

“Don’t,” Derek sighs. “I know better than that. You want to stir up some shit.” 

To literally no one’s surprise, really. Erica is certainly not the most patient member of the pack, and she has a soft spot a mile wide for her Alpha. She just wants him to be happy, to let himself experience some actual happiness for once instead of continuing to be stuck in the past (she’s confided in Stiles about this multiple times). Also, Erica just lives for some solid drama, and that’s just one of the many reasons why his Catwoman is a legend. 

Erica smirks. “Well, duh. I’m sick of your secretive, pathetic pining ass.” 

“Ooooooh,” Stiles gets in on it. “There’s pining? Actual pining? Derek, that’s adorable. Please don’t punch me for saying that.” 

Derek doesn’t do that anymore - not since the introduction of Stiles’ head to his steering wheel after he basically pimped Derek out to Danny. Still, Stiles notices the frustrated look on Derek’s face, and he just wants to be sure. 

“I’m not going to punch you, asshole,” Derek rolls his eyes like the sassmaster he is. 

“Awesome,” Stiles nods effusively. “Now can we talk about your mate without you whipping your claws out? You know how I get when there’s a mystery involved.” 

Obsessed. That’s how he gets. Like, he’s no House, but he has a little bit of Rubik’s syndrome - he’s a little too into puzzles and solving them. Maybe this is why he has no friends outside of the pack. Oh well, not like he needs those anyway. 

“I’m well aware,” Derek huffs. 

His arms are crossed over his chest, and Stiles isn’t staring at that at all, no sir. Because he’s not attracted to Derek. Not at all. 

“So?” Stiles needs more than that. 

“No.” Derek is smiling, though. 

So this is the game they’re playing? Fine, it’s on! 

“Derek!” Pout. 

“No.” 

“Pretty please with a cherry on top?” 

Wait, that wasn’t him! 

“Damn it, Erica,” Derek sighs mournfully. 

Are Erica and Derek the only people he’s interacted with since he got back? No, he has talked to his Dad a couple of times - and to Melissa, naturally. But whenever he is around Erica and/or Derek, this type of thing just tends to happen. And it will continue to happen until Stiles figures out what the deal is with werewolf mates, and he’s figured out just who Derek’s mate is. 

These are things that he simply has to know. 

“I’m sorry, was I supposed to let this continue for another hour?” Erica is impatient as usual. 

“Yes!” Both Stiles and Derek speak at exactly the same time. 

Clearly Derek enjoys this stupid bickering as much as Stiles does, and there’s no reason at all for that to warm his shrivelled heart. Sure, it’s nice to feel appreciated, because it’s not like Derek is ever going to be straightforward about how he likes having Stiles around. Let’s face it, it’s not like Stiles is ever going to be straightforward about how he likes having Derek around. 

Not just for the banter, but to have someone who’s seen him for exactly what he is, the best and the worst of him, and still treats him exactly the same: like the annoying little shit he’d been when he’d dragged Scott into the woods to find a body. Derek doesn’t coddle him, even after all the shit they’ve seen, and while he likes to keep Stiles as far away from the action as he can get him, he is always grateful when Stiles has to save his ass yet again. 

Well, Derek’s version of grateful, which involves a grunt in his general direction and a surprise appearance of his favorite snacks at the Pack house for the foreseeable future. He’s subtle like a sledgehammer like that. 

Seriously, Derek might as well just tell him who his mate is, because Stiles is going to find out in about two seconds. He’s a great detective. Derek doesn’t stand a chance. 

“Oh my fucking God,” Erica raises her hands to the sky. 

“You love me, Catwoman,” Stiles just grins at her, not moving an inch away from Derek. 

If Derek isn’t moving away, then neither is Stiles. Even though they literally have no personal space left anymore. Because they’re competitive assholes - oh, he wonders if that is an actual sport, because if so, that’s gonna be a gold medal for Stiles. Derek can have the silver. Maybe. 

“No wonder you don’t want to introduce your mate into the pack,” Stiles is trying to be sly. “This is a lot to deal with if you’re not an insider. Do they know about werewolves?” 

Because wow, he can’t imagine having to have that conversation. Sure, he’s part of a werewolf pack and has been for like six years now, but he’s never been in the position where he had to explain that to a significant other (he’s never dated much). Also, having to explain to someone that you were literally a mythical creature and that was why you knew that you were soulmates? That does not sound like a fun conversation - it sounds like the kind of talk that could get Derek arrested. Again. 

And this time it won’t even be Stiles’ fault in the slightest. 

“Not nearly as much as they think they do,” Derek arches his brows of sass at him. 

“On behalf of your mate, I take offense to that,” Stiles is not going to let Derek win. “You wolves are super secretive about your wolfy rituals. I didn’t even know that there was such a thing as mates until Erica told me, and I’ve been in your pack since junior year, basically.” 

It is kind of offensive that they play their cards so close to the vest, because Derek trusts Stiles. Stiles is a very trustworthy person, and he’s proven that to Derek about a million times over, ranging from that time with the bonesaw to the way he’s gone back for Derek every single fucking time, even when Scott flaked out. 

And for Derek not to tell him something that is such a huge deal for wolves, well… That’s just… Not cool. 

“Sophomore year,” Derek pointedly corrects him. 

Oh, wow. That is surprisingly sweet of him. 

“Really?” Stiles’ eyes are wide. “Back then too?” 

He can hear Erica facepalm in the background. 

* * *

Surprisingly, Derek is more subtle about the mate thing than he is about most everything else, because a few weeks go by and Stiles is still none the wiser. Erica has given up on talking to him about it, instead choosing to bring up her sexual relationship with Boyd every single time Stiles tries to pump her for information. 

And even Stiles has his limits when it comes to that. 

“So, books on mates?” Stiles finds himself asking Derek. “Is that a thing? Can I like, read up on it? I can totally help you court them. Or just make them feel more comfortable in a pack of wolves and creatures and such.” 

Derek stares at him. He says nothing. Which, for Derek… That’s just weird. He’s not actually the creepy lurker they thought he was back in high school. He’s one of the few people who can keep up with Stiles when it comes to sass. 

Or maybe Derek is surprised that Stiles is being relatively nice about it. Like, Derek clearly did not expect Stiles to basically start a welcoming committee for his mate. And well, screw Derek because Stiles can totally be nice to people - just as long as they aren’t Derek. He somehow isn’t able to be outwardly nice to Derek. 

Should he work on that at some point? Nah, the bickering works for them. 

“Do you mean to say the great Detective Stiles Stilinski hasn’t figured it out yet?” Derek finally comes in with the comeback. “I thought you were smarter than that. You always tell me how not subtle I am. I don’t think I’ve been subtle about this.” 

Wait, so Stiles has been missing the clues? There have been clues? Maybe he’s been a bit distracted due to all of the research he’s been doing into werewolf pack structure, hoping the books said anything at all about mates and mating rituals. If he were still the suspicious motherfucker he’d been in high school, he would have thought that Derek was purposefully keeping the books he needed from him. 

But why would he do that? It wasn’t like he wanted to have Stiles around all the time, digging through the Hale library at all hours of the day and night, crashing at Derek’s because he was too exhausted to drive himself home and he didn’t want to waste any research time by going home to his lonely single bed. 

Stiles isn’t lonely. He isn’t. He’s just… He actually, pathetically likes spending time with Derek now, because he keeps Stiles on his toes at all times and he enjoys that. Also, Derek basically challenged him to figure out the mate thing and Stiles cannot let him win. 

Though, apparently he’ll have to do that. Because Derek’s done with waiting for him to figure it out already, apparently. 

“You haven’t been?” Stiles is wracking his brain, trying to put together things that can be perceived as clues. 

He hasn’t even seen Derek interacting with anyone outside of the pack. So is it someone in the pack? But Isaac is basically the only unattached person in the pack, and if it were someone else, there would be a lot more angsting about it. Derek never needs another good reason to angst about something. He’s seemed… almost happy about this mate thing. 

So, Isaac? That doesn’t feel right. 

“For fuck’s sake, Stiles,” Derek has finally reached the end of his rope. “I’ve been flirting with you for months now. I make jokes about how big my dick is so that maybe you can be half as sexually frustrated as I’ve been. When we bicker, you basically wrap yourself around me and let me scent you. We went out to a movie together last week, and I paid for everything. You’ve slept in my bed three times over the past week. I have a perfectly adequate guest room. And you still have your own room here.” 

Months? Sure, he has noticed that there have been a couple more dick jokes than he expects from Derek, but he thought that was a sign that Derek was finally getting on his level. And the scenting? Well, he has worn Derek’s shirts on occasion and guiltily sniffed them and… oh.

_ Oh.  _

“I kissed you on the forehead last night, Stiles,” Derek puts the final nail in that coffin. 

Which, woah, yes, that had happened. And he never made a point of it, because it felt totally normal to have Derek do that, somehow. He hasn’t had much personal space issues around Derek, because they like to get up close and personal as they argue and Derek always stares at his mouth like he can make it… Oh my fucking God. 

He is an idiot. 

But...

“Wait a minute,” Stiles is making connections now. “You fucking insulted me, saying I didn’t know as much as I thought I did. You dick. You giant dick.” 

Derek just grins at him triumphantly, because he actually got the upper hand over Stiles without him even knowing it and that’s just… not fair. Stiles has to do something about that. And he has to do it now, before Derek gets even more smug. 

“How about I show you and your giant dick just how much I know about werewolves?”

Yes, that sentence is actually coming out of his mouth, and he’s not even ashamed, because Derek just stops in his tracks for a second (yes, point Stiles). Derek’s eyes are crimson now, and he cannot look away from Stiles (another point Stiles). 

Is this what winning feels like? Because it’s awesome. 

“I’m happy for you,” Erica interrupts, “but I need to not be here.” 

Wait, has she been here the whole time? Guess he really does get tunnel vision when Derek’s around. 

“Bye Erica,” he calls out after her. 

“Stiles,” Derek makes him turn back with just the sound of his voice. “You do know this is a forever type deal, right? Erica didn’t just tell you about the sex, did she?” 

Stiles rolls his eyes, because this idiot is choosing now to go soft on him? Really? It’s kind of really fucking adorable, but it’s also keeping Stiles from just dragging Derek into the bedroom (with the ridiculously comfortable bed that surely smells of both of them) and jumping him. 

“Give Catwoman some credit,” Stiles starts heading towards the bedroom anyway, knowing that Derek will follow like a good little werewolf. “She told me about the no divorce deal, about how it’s basically marriage plus.  _ And  _ she told me about the awesome sex. Which we’re having, stat. As soon you pull your head out of that awesome ass of yours.” 

Yep, that about does it for Derek. Compliments and insults mixed together. Awesome. Because that is absolutely what Stiles can offer him. That and awesome sex. 

Turns out, Erica is totally right about that part of the whole mating thing. 


End file.
